Crankshaft/layshaft centre to centre dimension?

[M996]

We are trying to repair an early sandcast engine block and after a bit of welding, I would like to line bore layshaft bearing bores.

Is there anyone here that has the centre to centre distance between the crankshaft and layshaft?

Will be very thankful for your help.

/Magnus

[safe]

I have never seen that measurement, but do you think that has ever changed across the engines?
The layshaft gears are interchangeable from a very early engine to a gt3, or at least an air-cooled 3.6, aren't they?
Do you have another known good case to take some measurements from?

Someone here must know for sure...

[chris_seven]

Do you mean the intermediate shaft?

If so there are two centre distances specified.

Crankcase marked with '0' 103.975 to 103.990mm

Crankcase marked with '1' 103.990 to 104.00

The crankshaft and intermediate shaft gears are also marked with '0' and '1' and there are varying combinations which will work but affect backlash.

I believe that there is a Table in Wayne's Book.

[Henry Schmidt]

If you're going to machine the sand cast lay shaft bearing saddles you might just as well machine them for bearings.
The early case (mag and sand cast) were manufactured sans removable bearings and no thrust surface. This mandating the need for a steel intermediate cover and shims to adjust end play. The shim are long since NLA (although we have a few and are in the process of re-manufacturing the shims and gaskets) so converting the case to a later intermediate shaft and using removable bearings is a nice upgrade.

[safe]

Clearly I haven't been reading the manuals thoroughly enough.

[Walt Fricke]

I have used a magnesium IS end plate on the sand cast case. Since oil under some pressure gets into the area between the end of the layshaft and the plate, I think the oil's pressure keeps the layshaft from boring a hole in the softer plate. Not had an issue with this, minimal marking on the plate. I use the mag plates because lighter, though by a trivial amount.

I had a machinist make a stainless shim for me when what I had wasn't getting the clearance needed. But if someone were to stock and sell those that would make things easier.

But the early IS shafts can be hard to come by, so machining to take the later shaft, plus the thrust and other bearings, makes good sense if you are busy machining other parts of the case.